Students prepare biological pesticides

Recognizing that many types of biological pesticides are available on the market but are expensive, while homemade products are not very effective, Hoang Nhi and Nong Hoang Lan conducted research with the hope of developing an effective, low-cost, and environmentally friendly product to control aphids, mealybugs, and other vegetable pests.

The main ingredients the students used to make the fertilizer included: Lao grass leaves, wild sunflower leaves, and tomato leaves; along with supplementary ingredients such as garlic, molasses, yeast, rice bran, and clean water. Among these, Lao grass (also known as bop bop, yen bach, bu xich…) is considered an ideal green manure plant, providing a high amount of organic biomass and rich nutrients to the soil. All parts of the plant contain essential oils, alkaloids, and tannins. This grass is also effective in controlling many types of plant fungi, eliminating flea beetle larvae and root nematodes, and repelling insects, termites, and leaf-eating caterpillars. Wild sunflowers (chrysanthemums, wild sunflowers…) are also a very good source of organic fertilizer for crops. In particular, wild sunflowers absorb insoluble potassium, convert it into soluble potassium, and store it in their stems, branches, and leaves. Therefore, when using fertilizer made from them, plants can easily absorb this potassium. According to scientific studies, the leaves of the wild sunflower contain sesquiterpene, diterpenoids, pyremethrin, alkaloids, flavonoids, tannins, saponins, etc., which are toxic to insects and pests. Tomato leaves, on the other hand, contain many gluco-alkaloid compounds, with tomanin being the main component. Tomanin is an antibacterial, antifungal, and pest-resistant agent. In addition, tomato leaves contain many alkaloids – substances that effectively kill and repel insects, especially aphids, moths, and other pests.

Hoang Nhi and Nong Hoang Lan, along with the product they researched and extracted.

After experimenting with different ratios of ingredients for fermentation, the research team determined the optimal ratio to be 2:4:1; the best fermentation time was 3 months. Accordingly, the production steps are as follows: Grind the leaves of the *Cynodon dactylon* plant, *Centella asiatica*, and tomato leaves together with a small amount of garlic, molasses, yeast, and rice bran. Put the mixture into a plastic jar and stir daily. After 3 months of fermentation, filter through a thin sieve to obtain the solution. The product costs approximately 25,000 VND/liter, which is much cheaper than other biological pesticides currently on the market.

After completing the experiments, the research team submitted the product to the Institute of Biotechnology and Environment at Tay Nguyen University for testing of the components and safety criteria of the biological pesticide. The results showed that the preparation contains alkaloids, which are toxic to aphids and other pests; it does not contain any components harmful to humans or the environment. When used to control aphids and other pests on sweet cabbage plants, the effectiveness was comparable to that of the biological pesticide Make Green 55WG. The number of sweet cabbage plants (in the experiment) affected by aphids and other pests was very low, there was no recurrence of aphids and other pests, and the plants grew and developed well.

Master Phan Minh Hai, a member of the Judging Panel for the Youth and Children's Innovation Competition, commented that the product created by the research group is novel and creative. The product utilizes locally available plants and inexpensive materials to create a highly effective, low-cost product that does not pollute the environment.

Doan Van Thanh

Source: https://baodaklak.vn/moi-truong/202509/hoc-sinh-dieu-che-thuoc-tru-sau-sinh-hoc-ac71392/